Hello, Gokulakrishnan!
Thank you for contacting Microsoft's Community.
Based on your inquiry, we understand you have passed the Exam AI-900: Microsoft Azure AI Fundamentals, however your Microsoft Certified: Azure AI Fundamentals is not visible on your Learn account. We will be happy to help you.
Note: With the changes implemented in our site on July 8th, our internal security policies were updated, and our Support Team is no longer able to confirm to our customers any personal information from their Learn Profiles, such as contact email address or email used to access their Learn profiles.
With this information provided, to locate your previously achieved Certifications, we advise following these steps using all the Microsoft accounts you may have associated with your Certification Profile in the past.
If you are still unable to find your certificate, we opened a Private Message where we have requested information related to your Learn account to verify it and properly assist you. You can find the access to the Private Message, on the top right corner of this screen, as shown in the image below.

We are looking forward to your information. Just a heads up, remember to only send your private information through private message, in order to protect your data.
If no response is received within two business days, we will proceed to close and lock this case as well as the Private Message.
kindly,